<template>
  <div class="list" ref='wrapper'>
    <div>
      <div class="area">
        <div class="title border-topbottom">当前城市</div>
        <div class="button-list">
          <div class="button-wrapper">
            <div class="button">{{this.currentCity}}</div>
          </div>
        </div>
      </div>
      <div class="area">
        <div class="title border-topbottom">热门城市</div>
        <div class="button-list">
          <div 
            class="button-wrapper" 
            v-for="item of hot" 
            :key="item.id"
            @click="handleCityClick(item.name)"
          >
            <div class="button">{{item.name}}</div>
          </div>
        </div>
      </div>
      <div 
        class="area" 
        v-for="(item,key) of cities" 
        :key="key"
        :ref="key"
      >
        <div class="title border-topbottom">{{key}}</div>
        <div class="item-list">
          <div 
            class="item border-bottom" 
            v-for="innerItem of item" 
            :key="innerItem.id"
            @click="handleCityClick(innerItem.name)"
          >
            {{innerItem.name}}
          </div>
        </div>
      </div>
     </div>
  </div>
</template>

<script>
import BScroll from 'better-scroll'
import { mapState, mapMutations } from 'vuex'
export default {
  name:'CityList',
  computed: {
   ...mapState({
     currentCity: 'city'  //这里使用的对象，就是把state中的city映射到这个组件的计算属性中这个值
   })
  },
  props: {  
    hot: Array,
    cities: Object,
    letter: String
  },
  methods: {
    handleCityClick (city) {
      // this.$store.commit('changeCity', city) 使用mutations的方法之前的调用
      this.changeCity(city)
      this.$router.push('/')
    },
    ...mapMutations(['changeCity'])   //使用mapMutations来简化mutations中的方法调用
  },
  mounted () {
    this.scroll = new BScroll(this.$refs.wrapper, { mouseWheel: true, click: true, tap: true })
  },
  watch: {
    letter () {
      if (this.letter) {
        const element = this.$refs[this.letter][0]
        this.scroll.scrollToElement(element)
      }
    }
  }
}
</script>
<style lang="stylus" scoped>
  @import '~styles/varibles.styl'
  .border-topbottom
    &:before
      border-color #ccc
    &:after
      border-color #ccc
   .border-bottom
    &:before
      border-color #ccc
  .list
    overflow hidden
    position absolute
    top 1.58rem
    left 0
    right 0
    bottom 0
    .title
      line-height .54rem
      background #eee
      padding-left .2rem
      color #666
      font-size .26rem
    .button-list
      padding .1rem .6rem .1rem .1rem
      overflow hidden 
      .button-wrapper
        float left
        width 33.33%
        .button
          margin .1rem
          padding .1rem 0
          text-align center
          border .02rem solid #ccc
          border-radius .06rem
    .item-list
    .item
      line-height .76rem
      padding-left .2rem
</style>
